A method for treating a disease comprising projecting a therapeutically effective light beam on at least a part of an eye of a wearer using a wearable device adapted for projecting a light beam on at least a part of an eye of a wearer of the wearable device, the wearable device having an optical module comprising a light source, a pupil being defined for the part of the eye, the wearable device comprising:
- a module adapted to provide the size of the pupil,
- a data processing unit adapted to determine a command law of the radiant power of the light source, the command law being determined on the provided pupil size, and
- a command module adapted to send the determined command law to the light source,
- wherein a maximum light intensity and a minimum light intensity are defined for the part of the eye and the command law further depends from at least one parameter selected in the group of the maximum light intensity and a minimum light intensity, each one of the maximum light intensity and the minimum light intensity varying spatially in the part of the eye.